In the photographic film processing industry it has long been recognized as desirable to mark the prints resulting from the development and processing of a batch of film with identification and/or processing data. This is typically done prior to or during the development and processing of film. A well-known prior art method for marking prints with data is to photograph alphanumeric data directly onto the film within the camera itself as the film is exposed or, alternately, within the developing/processing machine. Prints made from film so marked will accordingly display the data superimposed on the film image. The alphanumeric data is typically photographed onto the film by a light emitting diode (LED) array disposed near the film within the camera or in the developing/processing machine, which array can be selectively activated to generate various alphanumeric light characters in a well-known manner.
Another method has been to shine light through an opaque stencil directly onto the printing paper in the dark room during the exposure process.
U.S. Pat. No. 4,361,388 to Micak et al, relates to LED/fiber optic apparatus for marking data directly on a frame of film as it is exposed in the camera. A pedestal mounted on a plate in the camera housing supports an array of LED elements arranged in such a manner that a number of alphanumeric characters can be displayed by selectively lighting various portions of each element .in the array. A microprocessor incorporated within the camera operates the LED elements to display a set of characters corresponding to a particular frame of film being exposed. Fiber optic bundles overlying the LED elements transmit the characters displayed by the LED elements onto a frame of film, thereby permanently providing the frame with identifying data.
U.S. Pat. No. 3,987,467 to Cowles, relates to a system for marking previously exposed film with data while it is being processed in an automated machine prior to the making of prints therefrom, and simultaneously printing the data on a label or envelope corresponding to the film being marked. A continuous strip of film being fed into the machine is marked with data by an LED array whose light is focused onto the film by way of a system of lenses. The signal which activates the LED array is simultaneously sent to a printer, which prints the data on an envelope corresponding to that film. As an alternate embodiment, the Cowles patent teaches that other suitable means could be used to apply the data to the film, such as a fiber optic dot array or other illuminated display means, in place of the light source assembly.
U.S. Pat. No. 4,193,684 to Armstrong, relates to an apparatus for marking photographic negatives or prints with identifying data in the dark room. A contact printer enclosed in an opaque housing is placed over the film negative or print and a timed lamp is energized to project light through a light masking element or stencil to create a light image on the print.
An inherent disadvantage in marking the film itself is that the data marked thereon is permanent and will accordingly appear on every print resulting therefrom. It is therefore not possible to produce a print from the marked film negative without that data, or with any change in the data. A disadvantage inherent to contact printer lamp/stencil apparatus for forming light images on prints is the need for a change of stencils or masking elements each time a different set of data is to be marked on the print.